The present invention relates in general to tape for drywall construction, and in particular to a new and useful perforated paper tape having an adhesive back which expedites its application and use when constructing with wet wall, drywall, sheetrock and plasterboard products.
Any material or technique that decreases labor costs by reducing the time it takes to finish any particular part in a construction sequence would be welcomed by contractors. Labor productivity is a variable that most builders have at least some control over by utilizing the newest processes and tools.
The use of drywall or sheetrock is widely used for interior surfaces. For convenience the term drywall will be used in this disclosure to encompass sheetrock, plaster board and any other similar products which are provided in large area sheets for covering wall surfaces.
The first step in preparing seams in drywall construction for painting, is to apply tape to the seams. Such known tape is made of pulp paper and comes, for example, in rolls of 250 linear feet. The tape which is about 2 inches wide, is used in conjunction with a wet compound or plaster and requires a great deal of skill in its application to ensure that there are no wrinkles in the tape, bubbles under the tape or uneven layers of compound. The tape is then sanded and feathered so that when the wall is painted there are no seams showing.
While the forgoing process is time consuming and requires considerable skill for flat surface seams between drywall pieces, even greater skill is required for inside corner seams. To aid in the application of known paper tape to such seams, the known tape products are provided with a longitudinally extending central crush line which facilitates folding of the tape at its center and along its length.
In addition to paper tape, open fiberglass mesh has been used for the same purpose. The mesh is also supplied in 2 inch wide rolls and is in the form of a square mesh product with adhesive on one side. For application, the fiberglass mesh is first applied to the seam area and the wet compound is then applied over the top of the mesh and seam. Since no central fold line is provided, it is extremely difficult to use this type of product on inside corners. It is both difficult to fold the mesh exactly at its center and even more difficult to apply plaster using conventional knives which tend to rip the delicate mesh structure.
A wide variety of packing tapes are also known which have adhesive on one side, with or without a protective backing over the adhesive. None of these products are useful as seam tape in wet or drywall construction.
In designing seam tape of this type, the environment in which the tape will be applied and, for a much greater period of time, used, must be taken into account. Problems of wrinkles, bubbles and compatibility with compound both in its wet state and after it dries, must be taken into account.
A need remains for a seam tape product which avoids the high skill, time consuming application technique currently utilized, but which produces a long lasting effective seam.